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Tommy the cat
Well I remember it as though it were a meal ago...
Said Tommy the Cat as he reeled back to clear whatever foreign matter
may have nestled its way into his mighty throat. Many a fat alley rat
had met its demise while staring point blank down the cavernous barrel of
this awesome prowling machine. Truly a wonder of nature this urban
predator — Tommy the cat had many a story to tell. But it was a rare
occasion such as this that he did.
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You can find the finished example on GitHub (see also the source code).
Color
The color property sets the color of the foreground content of the selected elements, which is usually the text, but can also include a couple of other things, such as an underline or overline placed on text using the text-decoration property.
color can accept any CSS color unit, for example:
{
color: red;
}
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This will cause the paragraphs to become red, rather than the standard browser default of black, like so:
Font families
To set a different font for your text, you use the font-family property — this allows you to specify a font (or list of fonts) for the browser to apply to the selected elements. The browser will only apply a font if it is available on the machine the website is being accessed on; if not, it will just use a browser default font. A simple example looks like so:
{
font-family: arial;
}
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This would make all paragraphs on a page adopt the arial font, which is found on any computer.
Web safe fonts
Speaking of font availability, there are only a certain number of fonts that are generally available across all systems and can therefore be used without much worry. These are the so-called web safe fonts.
Most of the time, as web developers we want to have more specific control over the fonts used to display our text content. The problem is to find a way to know which font is available on the computer used to see our web pages. There is no way to know this in every case, but the web safe fonts are known to be available on nearly all instances of the most used operating systems (Windows, macOS, the most common Linux distributions, Android, and iOS).
The list of actual web safe fonts will change as operating systems evolve, but it's reasonable to consider the following fonts web safe, at least for now (many of them have been popularized thanks to the Microsoft Core fonts for the Web initiative in the late 90s and early 2000s):
Note: Among various resources, the cssfontstack.com website maintains a list of web safe fonts available on Windows and macOS operating systems, which can help you make your decision about what you consider safe for your usage.
Note: There is a way to download a custom font along with a webpage, to allow you to customize your font usage in any way you want: web fonts. This is a little bit more complex, and we will discuss it in a separate article later on in the module.
Default fonts
CSS defines five generic names for fonts: serif, sans-serif, monospace, cursive, and fantasy. These are very generic and the exact font face used from these generic names can vary between each browser and each operating system that they are displayed on. It represents a worst case scenario where the browser will try its best to provide a font that looks appropriate. serif, sans-serif, and monospace are quite predictable and should provide something reasonable. On the other hand, cursive and fantasy are less predictable and we recommend using them very carefully, testing as you go.
The five names are defined as follows:
Font stacks
Since you can't guarantee the availability of the fonts you want to use on your webpages (even a web font could fail for some reason), you can supply a font stack so that the browser has multiple fonts it can choose from. This involves a font-family value consisting of multiple font names separated by commas, e.g.,
{
font-family: "Trebuchet MS", Verdana, sans-serif;
}
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In such a case, the browser starts at the beginning of the list and looks to see if that font is available on the machine. If it is, it applies that font to the selected elements. If not, it moves on to the next font, and so on.
It is a good idea to provide a suitable generic font name at the end of the stack so that if none of the listed fonts are available, the browser can at least provide something approximately suitable. To emphasize this point, paragraphs are given the browser's default serif font if no other option is available — which is usually Times New Roman — this is no good for a sans-serif font!
Note: Font names that have more than one word — like Trebuchet MS — need to be surrounded by quotes, for example "Trebuchet MS".
A font-family example
Let's add to our previous example, giving the paragraphs a sans-serif font:
p {
color: red;
font-family: Helvetica, Arial, sans-serif;
}
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This gives us the following result:
Font size
In our previous module's CSS values and units article, we reviewed length and size units. Font size (set with the font-size property) can take values measured in most of these units (and others, such as percentages); however, the most common units you'll use to size text are:
px (pixels): The number of pixels high you want the text to be. This is an absolute unit — it results in the same final computed value for the font on the page in pretty much any situation.
ems: 1 em is equal to the font size set on the parent element of the current element we are styling (more specifically, the width of a capital letter M contained inside the parent element). This can become tricky to work out if you have a lot of nested elements with different font sizes set, but it is doable, as you'll see below. Why bother? It is quite natural once you get used to it, and you can use em to size everything, not just text. You can have an entire website sized using em, which makes maintenance easy.
rems: These work just like em, except that 1 rem is equal to the font size set on the root element of the document (i.e. ), not the parent element. This makes doing the maths to work out your font sizes much easier, although if you want to support really old browsers, you might struggle — rem is not supported in Internet Explorer 8 and below.
The font-size of an element is inherited from that element's parent element. This all starts with the root element of the entire document — — the standard font-size of which is set to 16px across browsers. Any paragraph (or another element that doesn't have a different size set by the browser) inside the root element will have a final size of 16 px. Other elements may have different default sizes. For example, an element has a size of 2 em set by default, so it will have a final size of 32 px.
Things become more tricky when you start altering the font size of nested elements. For example, if you had an element in your page, and set its font-size to 1.5 em (which would compute to 24 px final size), and then wanted the paragraphs inside the elements to have a computed font size of 20 px, what em value would you use?
My paragraph
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You would need to set its em value to 20/24, or 0.83333333 em. The maths can be complicated, so you need to be careful about how you style things. It is best to use rem where you can to keep things simple, and avoid setting the font-size of container elements where possible.
A simple sizing example
When sizing your text, it is usually a good idea to set the base font-size of the document to 10 px to make the maths a lot easier to work out — required (r)em values are then the pixel font size divided by 10, not 16. After doing that, you can easily size the different types of text in your document to what you want. It is a good idea to list all your font-size rulesets in a designated area in your stylesheet, so they are easy to find.
Our new result is like so:
html {
font-size: 10px;
}
{
font-size: 5rem;
}
{
font-size: 1.5rem;
color: red;
font-family: Helvetica, Arial, sans-serif;
}
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Font style, font weight, text transform, and text decoration
CSS provides four common properties to alter the visual weight/emphasis of text:
font-style: Used to turn italic text on or off. Possible values are as follows (you'll rarely use this, unless you want to turn some italic styling off for some reason):
normal: Sets the text to the normal font (turns existing italics off).
italic: Sets the text to use the italic version of the font, if available; if not, it will simulate italics with oblique instead.
oblique: Sets the text to use a simulated version of an italic font, created by slanting the normal version.
font-weight: Sets how bold the text is. This has many values available in case you have many font variants available (such as -light, -normal, -bold, -extrabold, -black, etc.), but realistically you'll rarely use any of them except for normal and bold:
normal, bold: Normal and bold font weight.
lighter, bolder: Sets the current element's boldness to be one step lighter or heavier than its parent element's boldness.
100–900: Numeric boldness values that provide finer grained control than the above keywords, if needed.
text-transform: Allows you to set your font to be transformed. Values include:
none: Prevents any transformation.
uppercase: Transforms all text to capitals.
lowercase: Transforms all text to lower case.
capitalize: Transforms all words to have the first letter capitalized.
full-width: Transforms all glyphs to be written inside a fixed-width square, similar to a monospace font, allowing aligning of, e.g., Latin characters along with Asian language glyphs (like Chinese, Japanese, Korean).
text-decoration: Sets/unsets text decorations on fonts (you'll mainly use this to unset the default underline on links when styling them). Available values are:
none: Unsets any text decorations already present.
underline: Underlines the text.
overline: Gives the text an overline.
line-through: Puts a strikethrough over the text.
You should note that text-decoration can accept multiple values at once if you want to add multiple decorations simultaneously, for example, text-decoration: underline overline. Also note that text-decoration is a shorthand property for text-decoration-line, text-decoration-style, and text-decoration-color. You can use combinations of these property values to create interesting effects, for example: text-decoration: line-through red wavy.
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